Entries in Lake Huron
(9)

Atlantic salmon fingerlings. USFWS photoA chance discovery by a college student reveals that Atlantic salmon are reproducing in the Great Lakes --- at least in the St. Mary’s River, which connects Superior and Huron.

“We were conducting research for my sturgeon thesis when we found the Atlantic salmon fry,” said StefanTucker, a Lake Superior State University graduate. “It was very exciting to everyone who was a part of my research to imagine what we had just stumbled upon.

“While sorting through my samples at the lab with Roger (Greil), we began to ID the salmonids and Roger had a suspicion that they were Atlantics,” he added. “We caught wild Atlantics in our next two sampling events, so we wanted to confirm our ID and we sent a few to Dr. Gerald Smith at University of Michigan, who confirmed the identification.

Atlantic salmon (Salmo salar) are native to Lake Ontario, but their populations severely declined by the late 1800s, according to Tucker’s abstract. During the early to mid-1900s, Atlantic salmon were stocked throughout the Great Lakes in effort to reestablish them into Lake Ontario and introduce the species into the upper Great Lakes. However, these efforts had minimal success.

In 1987, LSSU, in cooperation with MDNR Fisheries, began stocking Atlantic salmon in the St. Mary’s River. While the effort has resulted in a very successful recreational fishery, along with an excellent educational experience for students, it appeared that Atlantics were still not reproducing naturally even though they would return to the river spawning grounds every year. Biologists wondered if competition from other salmonids spawning in the St. Mary’s in greater numbers – including chinook and pink salmon – was keeping Atlantics from thriving.

While this is the first documentation of natural reproduction of Atlantic salmon in the upper Great Lakes, Tucker’s study concludes that “the extent of natural reproduction and mechanisms influencing reproductive success are unclear and warrant further attention.”

Good news from Lake Huron, where lake trout seem to be reproducing --- finally.

First, sea lamprey migrated into the Great Lakes from the Atlantic Ocean and nearly obliterated them. Resource managers have managed to minimize the impacts of this blood-sucking invader, with millions of dollars spent on mitigation.

Then the alewife, another exotic species, complicated recovery. As they fed on the prolific baitfish, lake trout sustained a vitamin deficiency that damaged reproduction. Supplemental stocking by the federal government did little to sustain the population.

But about a decade ago, the alewife population collapsed, probably because an overabundance of predatory salmon, yet another introduced species.

So, with lamprey minimized and lake trout now getting the nutrients they need from native forage, they finally are successfully reproducing and could be on the road to recovery, according to Michigan Radio.

“I felt we were so completely stymied by one thing after another after another. The litany of challenges working against the reestablishment of a self-sustaining lake trout population seemed insurmountable,” said Jim Johnson of the Michigan Department of Natural Resources. “But then, with the collapse of alewives, everything changed.”

Anglers and recreational boaters were warned in late fall of dangerously reduced water levels in Lakes Michigan, Huron, and Superior, with a likelihood of all three falling to record lows in early 2013.

Michigan and Huron were 11 inches lower than the year before and 2 feet, 4 inches lower than their long-term averages for October. Superior was at its 1925 record-low average for that month.

Mostly, the decline is blamed on a mild winter with little snow followed by a hot summer with little rain, according to Keith Kompoltowicz, a hydrologist for the U.S. Army Corps of Engineers.

“We are seeing much lower water levels than we had last year, and that is the case all over the Great Lakes,” he said.

But more and more, attention is turning to what man has been done to alter the water levels and what might be done in the way of mitigation. For example, reversing the Chicago River in 1900 so it flowed out of Lake Michigan instead of into it resulted in a loss of about 2.1 billion gallons a day, which has dropped the long-term average for both Michigan and Huron by two inches.

Key focus, though, is on the St. Clair River, which has been heavily dredged, allowing more water to flow out of Huron and into Erie and, from there, eventually into the Atlantic Ocean. Scientists generally believe this alteration has resulted in a drop of the long-term average for Huron and Michigan by about 16 inches. But a recent joint study by the U.S. and Canada suggests that erosion in the St. Clair might have reduced the long-term average for those two lakes by an additional 3 to 5 inches.

That has prompted a coalition of mayors from 90 cities around the Great Lakes to ask the International Joint Commission, which advises on boundary water issues, to further investigate engineering options to raise lake levels in order “to compensate for human activities, notably dredging in the St. Clair River . . .”

Another group, Save Our Shoreline, wants a mechanism to control water flow in the St. Clair.

“Given the history of consistent water level reductions since 1855, the unmitigated and unplanned increase in conveyance in the St. Clair River since 1962, and the uncertainties presented by climate change, we believe it would be irresponsible not to begin the process toward a regulatory structure now,” it said.

Water levels on the Great Lakes typically fluctuate by inches seasonally and by as much as several feet over a period of years. But, until now, anglers, marina operators, and lakefront property owners felt secure in believing that water levels wouldn’t drop below the 1964 record lows.

Zebra mussel shells have closed the entrance to a channel near Point Comfort in the Town of Black Wolf. Residents have found attempts to clear the channel futile as the shells always accumulate again quickly after being removed. / Oshkosh Nortwestern photo by Adam Jungwirth

With some accuracy, we can predict what the consequences will be when an exotic species becomes established outside its native range.

For example, we believed that zebra mussels would form large colonies, blocking water intakes. And we suspected that they would outcompete native mussel species for habitat.

They have done both, of course.

But invasive species also bring with them unforeseen consequences, which can be even more catastrophic that the predicted damage.

We knew that zebra mussels were filter feeders, but we little suspected that they could alter ecosystems as massive as the Great lakes because of that behavior. Yet they have: The Lake Huron fishery is collapsing as a direct result, and the Lake Michigan fishery is following in its wake.

And we never thought that zebra mussels would pair with another invasive, the round goby, to create a toxic cocktail that would kill thousands of loons and other birds. But they have: The birds die of botulism, contracted from eating round gobies, which ate the mussels.

And now, here’s a new wrinkle:

On Wisconsin’s Lake Winnebago, zebra mussels are piling up along the shoreline, creating all kinds of unforeseen problems.

Starting about two years ago the shell remnants of these tiny, striped mollusks, about the size of a fingernail, formed a barrier on the channel's lakefront border a couple feet tall and thick enough to walk on.

This wall keeps fishing boats, fish and fresh water from passing freely between nearby Lake Winnebago and the channel, leaving only stagnant water behind in the passageway. It has become a source of frustration for residents in about a dozen homes around the channel who had enjoyed easy access to the lake in the past and fishing for bluegill and crappie near their backyards.

"There's nothing coming through, and there's no fish in the channel," said Dave Ratajczak, owner of one of the channel properties. "It's bad when you own a boat and you can't even get out."

Zebra mussels are a small, invasive mollusk from Eastern Europe that arrived in the Great Lakes in the 1980s by hitching a ride on ocean-going ships.

Ron Bruch, fisheries supervisor at the DNR, said boats from the Great Lakes brought the mussels into the Lake Winnebago system. They were discovered in Lake Winnebago in 1998, with their numbers peaking in the early 2000s.

"There's no way of dealing with them, other than just to live with them," he said.

Now let’s consider the Asian carp. We think that we know what will happen if they enter the Great Lakes, based on the decimation that they’ve caused in rivers. But considering the zebra mussel example, the actual havoc that they will wreak probably is unimaginable.

I long ago accepted the fact that stupid decisions are made regarding management of waters and lands.

Still, sometimes the immenseness of that stupidity staggers me. That’s the case this time with the intentional introduction of zebra mussels in Great Britain.

This article says that the mussels “were introduced to clean up the water.”

And an official responsible for this insanity says, "We want to keep the water as clean as possible and as clear as possible so the whole society can benefit.

"People can now walk along the quayside (at Salford Quays) and see clean and clear water."

I’ll bet that they can. Aquatic life has been sucked right out of the water.

These are the same mussels that have collapsed the food chain in Lake Huron and are well on their way to doing the same in Lake Michigan. They do so by gobbling phytoplankton and zooplankton with their rapacious filter-feeding.

Along with their quagga mussel cousins, they also have been linked to an increase in toxic algae blooms in the Great Lakes, as well as outbreaks of avian botulism that have killed thousands of loons and other birds.

And of course, these invaders are costly. Governments and industries must spend billions annually to keep them from blocking water intakes.

Let’s not forget, too, that they easily spread from one water body to another in livewells and bilges, as well as on boat hulls and trailers.

Back in Britain, meanwhile a fishing club has disbanded because its members have failed to catch a single fish during their last four competitions in the mussel-infested waters.

And the company that introduced the mussels denies that they are to blame for the fisheries decline.